Synthesis And Evaluation Of Anti - Temperature And Salt - Resistant Drilling Fluid

The paper synthesizes the new copolymer——PAAAC with a good resistance to temperature and salt properties, using 2-acrylamido-2-methylpropanesulfonicacid (AMPS), acrylamide(AM), acrylonitrile(AN) and acrylic acid (AA) as main materials and ammonium persulfate as initiators in aqueous solution system. Through single factor experiment and an orthogonal test we sure the optimum reaction condition is as follow:AMPS:AM:AA:AN =2.5:5.5:1:1, initiator amount 0.15%, monomer amount 35%,reaction temperature 50℃,pH=8and reaction time is 5 hours. PAAAC with Fourier transform infrared characterized the structure of molecules that do not exist carbon-carbon double bond that means react exactly. At room temperature, in fresh water mud system, with the polymer amount of 1.5%, dehydration is separately the 4.8mL; In 4% salt water, saturated brine mud and composite salt water mud system, with the polymer amount of 2.5%, the dehydration is separately the 14.8mL,15.8mL and 14.6mL. At 220℃,In fresh water mud system, with the polymer amount of 2.0%, dehydration is separately the 9.2mL;In 4% salt water, saturated brine mud and composite salt water mud system, with the polymer amount of 2.5%,dehydration is 16.8mL, 20mL and 19mL.The dehydration is separately the 12.6mL with 700mg/L Ca2+composite salt water mud and the PAAAC amount of 2.5%, the dehydration is separately the 56mL and 63mL in 700mg/L Ca2+composite salt water with SL-land MAN-101. With the polymer amount of 0.6%, the first recovery percent,the second recovery percent and relative recovery percent is 93.7%、90.4% and 96.5%。Because of salt resistant effect is not ideal will PAAAC and the synthesis of income SMC, SMP-Ⅱwater-based fluid drop filter material to complex formulation. In 4% salt water mud system, at room temperature and 220℃,the dehydration is separately the 6.0 and 8.0mL;In composite salt water mud system, at room temperature and 220℃,the dehydration is separately the 7.8 and 8.0mL.The experiment proof that TAC and SMC, SMP-Ⅱhas good blends with performance, and has the ideal of temperature-to-resistance salt resistant performance.